[PATCH] sanlock: WAIT flag for sanlock_inq_lockspace

[Federico Simoncelli]

New SANLK_INQ_WAIT for sanlock_inq_lockspace().

When the SANLK_INQ_WAIT flag is used the command will block and wait for
the ongoing procedure (add_lockspace/rem_lockspace) to complete before
before returning the status.

sanlock_inq_lockspace() still returns:

0               lockspace exists and is not being added or removed
-EINPROGRESS    add or rem is in progress, when the flag SANLK_INQ_WAIT
                is not used
-ENOENT         no lockspace with matching name and disk location is
                found

Signed-off-by: Federico Simoncelli 
---
 python/sanlock.c    |   25 +++++++++++++++++--------
 src/cmd.c           |   15 ++++++++++++---
 src/sanlock_admin.h |    3 +++
 3 files changed, 32 insertions(+), 11 deletions(-)

diff --git a/python/sanlock.c b/python/sanlock.c
index bfce46c..d953c90 100644
--- a/python/sanlock.c
+++ b/python/sanlock.c
@@ -314,36 +314,45 @@ py_add_lockspace(PyObject *self __unused, PyObject *args, PyObject *keywds)

/* inq_lockspace */
 PyDoc_STRVAR(pydoc_inq_lockspace, "\
-inq_lockspace(lockspace, host_id, path, offset=0)\n\
+inq_lockspace(lockspace, host_id, path, offset=0, wait=False)\n\
 Return True if the sanlock daemon currently owns the host_id in lockspace,\n\
 False otherwise. The special value None is returned when the daemon is\n\
-still in the process of acquiring or releasing the host_id.");
+still in the process of acquiring or releasing the host_id. If the wait\n\
+flag is set to True the function will block until the host_id is either\n\
+acquired or released.");

static PyObject *
 py_inq_lockspace(PyObject *self __unused, PyObject *args, PyObject *keywds)
 {
-    int rv;
+    int rv, waitrs = 0, flags = 0;
     const char *lockspace, *path;
     struct sanlk_lockspace ls;

-    static char *kwlist[] = {"lockspace", "host_id", "path", "offset", NULL};
+    static char *kwlist[] = {"lockspace", "host_id", "path", "offset",
+                                "wait", NULL};

/* initialize lockspace structure */
     memset(&ls, 0, sizeof(struct sanlk_lockspace));

/* parse python tuple */
-    if (!PyArg_ParseTupleAndKeywords(args, keywds, "sks|k", kwlist,
-        &lockspace, &ls.host_id, &path, &ls.host_id_disk.offset)) {
+    if (!PyArg_ParseTupleAndKeywords(args, keywds, "sks|ki", kwlist,
+        &lockspace, &ls.host_id, &path, &ls.host_id_disk.offset,
+        &waitrs)) {
         return NULL;
     }

+    /* prepare sanlock_inq_lockspace flags */
+    if (waitrs) {
+        flags |= SANLK_INQ_WAIT;
+    }
+
     /* prepare sanlock names */
     strncpy(ls.name, lockspace, SANLK_NAME_LEN);
     strncpy(ls.host_id_disk.path, path, SANLK_PATH_LEN - 1);

/* add sanlock lockspace (gil disabled) */
     Py_BEGIN_ALLOW_THREADS
-    rv = sanlock_inq_lockspace(&ls, 0);
+    rv = sanlock_inq_lockspace(&ls, flags);
     Py_END_ALLOW_THREADS

if (rv == 0) {
@@ -362,7 +371,7 @@ py_inq_lockspace(PyObject *self __unused, PyObject *args, PyObject *keywds)
 PyDoc_STRVAR(pydoc_rem_lockspace, "\
 rem_lockspace(lockspace, host_id, path, offset=0, async=False, unused=False)\n\
 Remove a lockspace, releasing the acquired host_id. If async is True the\n\
-function will return immediatly and the status can be checked using\n\
+function will return immediately and the status can be checked using\n\
 inq_lockspace. If unused is True the command will fail (EBUSY) if there is\n\
 at least one acquired resource in the lockspace (instead of automatically\n\
 release it).");
diff --git a/src/cmd.c b/src/cmd.c
index 6417df0..de82ff7 100644
--- a/src/cmd.c
+++ b/src/cmd.c
@@ -891,6 +891,7 @@ static void cmd_add_lockspace(struct cmd_args *ca)
 static void cmd_inq_lockspace(struct cmd_args *ca)
 {
    struct sanlk_lockspace lockspace;
+	int waitrs = ca->header.cmd_flags & SANLK_INQ_WAIT;
    int fd, rv, result;

fd = client[ca->ci_in].fd;
@@ -903,13 +904,21 @@ static void cmd_inq_lockspace(struct cmd_args *ca)
    	goto reply;
    }

-	log_debug("cmd_inq_lockspace %d,%d %.48s:%llu:%s:%llu",
+	log_debug("cmd_inq_lockspace %d,%d %.48s:%llu:%s:%llu flags %x",
    	  ca->ci_in, fd, lockspace.name,
    	  (unsigned long long)lockspace.host_id,
    	  lockspace.host_id_disk.path,
-		  (unsigned long long)lockspace.host_id_disk.offset);
+		  (unsigned long long)lockspace.host_id_disk.offset,
+		  ca->header.cmd_flags);
+
+	while (1) {
+		result = inq_lockspace(&lockspace);
+		if ((result != -EINPROGRESS) || !(waitrs)) {
+			break;
+		}
+		sleep(1);
+	}

-	result = inq_lockspace(&lockspace);
  reply:
    log_debug("cmd_inq_lockspace %d,%d done %d", ca->ci_in, fd, result);

diff --git a/src/sanlock_admin.h b/src/sanlock_admin.h
index c5a3a0f..5134faa 100644
--- a/src/sanlock_admin.h
+++ b/src/sanlock_admin.h
@@ -17,6 +17,9 @@
 #define SANLK_REM_ASYNC		0x00000001
 #define SANLK_REM_UNUSED	0x00000002

+/* inq flags */
+#define SANLK_INQ_WAIT		0x00000001
+
 /*
  * add_lockspace returns:
  * 0: the lockspace has been added successfully